Windows10 WSL2 Ubuntu / Debian # no network [closed]

After upgrading from WSL to WSL2

sudo apt-get update

not works any longer. After:

wsl --set-version Ubuntu-18.04 2

Output is:

> sudo apt-get updateErr:1 http://security.ubuntu.com/ubuntu bionic-security InRelease  Temporary failure resolving 'security.ubuntu.com'Err:2 http://archive.ubuntu.com/ubuntu bionic InRelease  Temporary failure resolving 'archive.ubuntu.com'Err:3 http://archive.ubuntu.com/ubuntu bionic-updates InRelease  Temporary failure resolving 'archive.ubuntu.com'Err:4 http://archive.ubuntu.com/ubuntu bionic-backports InRelease  Temporary failure resolving 'archive.ubuntu.com'Reading package lists... DoneW: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/bionic/InRelease  Temporary failure resolving 'archive.ubuntu.com'W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/bionic-updates/InRelease  Temporary failure resolving 'archive.ubuntu.com'W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/bionic-backports/InRelease  Temporary failure resolving 'archive.ubuntu.com'W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/bionic-security/InRelease  Temporary failure resolving 'security.ubuntu.com'W: Some index files failed to download. They have been ignored, or old ones used instead.

After going back to WSL1 the problem disappears again. Same on Debian and analogous in CentOS .. so WSL2 must have a bug.

The Windows10 build Version is 19041 and was installed today.

Any work around for WSL2?Regards